Method of forming oil grooved bushings



March 1, 1932. E, PREN'HCE 1,847,099

METHOD OF FORMING OIL GROOVED BUSHINGS Filed Aug. 14, 1928 Patented Mar. 1, 1932 UNHTED STATES PATENT OFFECE EARL PRENTICE, OF NEW CASTLE, PENNSYLVANIA, ASSIGNOR TO JOHNSON BRONZE 4 COMPANY, OF NEW CASTLE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA METHOD or FORMING 01 enoovnn nusnrnes Application filed August 14, 1928. Serial No. 299,581.

This invention relates to bushings, and more particularly to bushings formed of bearing metal and having oil grooves therein, the invention pertaining to a groove and a method of forming the same which will be open at its end.

In the usual practice of making oil grooved bushings, grooves are formed by punching, rolling, or by other means in a. flat strip of bearing metal, such as bronze. The blanks from which the bushings are formed are cut from the strip, bent into cylindrical form and finally chamfered on the ends. The chamfering tool frequently closes the ends of the oil grooves and it is necessary to open the grooves by hand after the bushings have been chamfered.

The present invention relates to the formation of the oil grooves in such a way that the groloves will not be closed by the chamfering too The invention may be readily understood by reference to the accompanying drawings, in which Figure 1 is an end elevation of a die for grooving a strip and cutting a blank therefrom;

Figure 2 is a bottom view of the die shown in Figure 1;

Figure 3 is a blank formed in accordance with the present invention; and I Figure 4; is a perspective view of the completed bushing.

In the drawings, 2 designates a die having a groove forming portion 3 and a blanking out portion 4. By reference to Figure 2 it will be seen that the portion 3 has ridges 3 thereon arranged in any preferred manner. The portion 3 is intended to press grooves into a length of strip of just the right dimension for forming the bushing.

In the operation of the die the strip is first fed under the portion 3 of the die where grooves 5 are formed therein by the ridges 3 on the die. The strip then passes under the portion 4 of the die which cuts a blank 6 out of the strip. This blank is shown in Figure 3 The blank 6 is then bent into a cylindrical bushing, as shown in Figure 4.

So much of the general arrangement and operation as has been described is now common practice 1n the art and forms no part of the present invention.

According to the present invention each of the groove forming ribs 3 has a terminal portion 3 which is widened out to twice the width of the portion 3 This results in the formation of a blank wherein the grooves 5 have a widened end 5 at the point where such grooves meet the edges of the blank.

WVhen the strip 6 having grooves so formed is made into a bushing and is chamfered, as indicated at 7 in Figure 4, the ends of the oil grooves 8 in the finished bushing are open and clean. This is entirely due to the increased width of the terminal portions of the grooves 5 in the blank. Instead of the metal being wiped across the ends of the grooves, as happens where the grooves are of uniform width clear to the edge, the metal is cut off by the chamfering tool where the groove is widened and if the metal is wiped around with the chamfering tool, it will carry only part way across the widened terminal of the slot and not all the way across. It has been found that by making the terminal portions of the grooves about twice as wide as the grooves themselves, the most desirable results are secured.

By reason of this invention it is assured that all of the grooves will remain open after being chamfered even when the bearing is formed of metal like bronze wherein the chamfering tool tends to wipe the metal around instead of cutting it clean.

In the drawings the grooves are shown as being arranged in an X-like formation, but the invention is applicable to grooves arranged in any way wherein the grooves extend to the edge of the bushing.

I claim:

1. The method of forming oil grooved bushings having a groove which opens at one end of the bushing, which comprises forming the groove with an offset portion therein providing a widened end and subsequently chamfering the bushing.

2. The method of forming oil grooved bushings which comprises forming a sheet metalblank having grooves therein with the terminals of the grooves widened transversely of the width of the grooves, forming the blank into a bushing, and chamfering the ends thereof.

3. The method of forming oil grooved bushings from sheet metal blanks which comprises forming oil grooves in a blank with the terminals of the grooves flared out be yond the normal Width of the grooves the transverse width of the grooves at such terminals being greater than the normal-transverse width of the grooves, bending the blank to shape, and then chamfering the bushing; said widened ends of the grooves serving to maintain the ends of the grooves open against the action of the chamfering tool.

4:. The method of making oil grooved bushings which comprises forming ablank having oil grooves therein, the ends of the grooves being approximately twice the normal width of the grooves, forming the blank into a cylinder and then chamfering the ends of the cylinder.

5. As an intermediate article of manufacture, a sheet metal bushing blank which is to be subsequently subjected to the action of a chamfering tool, said blank having oil grooves in the face thereof, which grooves intersect the margin of the blank, the end portions of the grooves having an offset to provide enlarged terminal portions for the ends of the groove.

In testimony whereof- I have hereunto set my hand.

EARL PRENTICE. 

